Free-Standing N-Doped Carbon Nanotube Films with Tunable Defects as a High Capacity Anode for Potassium-Ion Batteries
Free-Standing N-Doped Carbon Nanotube Films with Tunable Defects as a High Capacity Anode for Potassium-Ion Batteries
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DOI：
10.1021/acsami.0c12288
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发表时间：
2020-08-19
影响因子：
9.5
通讯作者：
Liu, Xianghong
中科院分区：
文献类型：
--
作者：
Wang, Kai;Li, Ningning;Liu, Xianghong
钾离子电池已经引起了人们对未来储能技术的极大兴趣。然而，目前的KIBS阳极存在容量衰落快、倍率性能差等问题。在这里，我们展示了一种独立的柔性阳极，即掺氮碳纳米管纸(NCTP)，它是由有机聚吡咯材料热解而来的，用于高性能的钾存储。通过一系列材料分析和表征，以及电化学测试，研究了材料结构与电化学性能之间的关系。研究结果表明，退火温度对样品的N掺杂含量、碳缺陷和石墨化程度有显著影响。电化学测试表明，在700℃下热处理的NCTP具有最好的性能，在100 mA g(-1)时的可逆容量为250.1 mA h g(-1)，在5A g(-1)时的倍率性能为133 mA h g(-1)。这种优异的电化学性能源于材料中适度的N掺杂、碳缺陷和高电子传导性的协同贡献。本工作所涉及的简单的热解策略和吸引人的性能可以为操纵高性能的KIBS负极材料提供一些线索。
Potassium-ion batteries (KIBs) have aroused enormous interest for future energy storage technology. However, the current anodes for KIBs greatly suffer from the rapid capacity fading and inferior rate capability. Herein, a free-standing flexible anode, that is, nitrogen-doped carbon nanotube paper (NCTP), which is derived from the pyrolysis of organic polypyrrole materials, is demonstrated for high-performance potassium storage. The correlations between the material structure and electrochemical properties have been investigated by a series of material analysis and characterizations, as well as electrochemical tests. The research results show that the annealing temperature dramatically affects the N-doping content, the carbon defects, and the graphitization degree. Electrochemical tests indicate that the NCTP annealed at 700 degrees C displays the best performances with a high reversible capacity of 250.1 mA h g(-1) at 100 mA g(-1) and superior rate capability retaining 133 mA h g(-1) at 5 A g(-1). The excellent electrochemical properties are derived from a synergic contribution from the moderate N-doping, carbon defect, and high electronic conductivity of the materials. The facile pyrolysis strategy and the appealing performances involved in this work could provide some hints to manipulate high-performance anode materials of KIBs.